1. Field of the Invention
The present invention relates to a display device such as a liquid crystal display device, and particularly to a display device whose transmissivity can be improved by reducing the diameter of a contact hole formed in an organic film in a pixel circuit portion of a substrate.
2. Description of the Related Art
In a display device such as a liquid crystal display device, provided are an array substrate (or referred to as a TFT substrate) on which pixel electrodes, thin film transistors (TFTs), and the like are formed in a matrix shape, and an opposed substrate which faces the array substrate and on which color filters and the like are formed at positions corresponding to the pixel electrodes of the array substrate. In addition, liquid crystal is sandwiched between the array substrate and the opposed substrate. The transmissivity of light by liquid crystal molecules is controlled for each pixel to form an image.
As described in Japanese Patent Application Laid-Open No. Hei 9-304793, an attempt to improve the aperture ratio of each pixel in a recent liquid crystal display device has been known. The liquid crystal display device disclosed in Japanese Patent Application Laid-Open No. Hei 9-304793 includes a buried portion to fill a recessed portion generated by forming a pixel electrode in a contact hole formed to connect a thin film transistor and the pixel electrode to each other. Accordingly, the disturbance of orientation of liquid crystal molecules in the contact hole of an organic passivation film can be suppressed, and light transmission is prevented without decreasing the aperture ratio of each pixel of the liquid crystal display device.